Skip to main content


First archeointensity results from Portuguese potteries (1550-1750 AD)

Article metrics

  • 244 Accesses

  • 12 Citations


Geomagnetic field variations at archeomagnetic timescales can be obtained from well-dated heated structures and archeological potsherds. Here, we present the first archeointensity results obtained on Portuguese ceramics (1550 to 1750 AD) collected at Brazilian archeological sites. The results are compared to those obtained from Western Europe and currently available geomagnetic field models. Continuous thermomagnetic and IRM acquisitions curves indicate that Ti-poor titanomagnetite is responsible for the remanence in these ceramic fragments. Five fragments (24 samples) out of twelve analyzed yielded reliable intensity estimates. The row archeointensity data were corrected for TRM anisotropy and cooling rate effect. The mean dipole moments are obtained for three different age intervals: 1550±30 AD, 1600±30 AD and 1750±50 AD. Mean intensities vary from 37.9±4.2 μT to 54.8±7.6 μT in agreement with the previously reported data for 1550 AD and 1750 AD. Relatively weaker, but still highly dispersed, values were obtained for 1600 AD ceramics.


  1. Aitken, M. J., A. L. Allsop, G. D. Bussell, and M. B. Winter, Determination of the intensity of the Earth’s magnetic field during archaeological times: Reability of the Thellier technique, Rev. Geophys., 26, 3–12, 1988.

  2. Bowles, J., J. Gee, J. Hildebrand, and L. Tauxe, Archaeomagnetic intensity results from California and Ecuador: evaluation of regional data, Phys. Earth Planet. Inter., 203(3-4), 967–981, 2002.

  3. Chauvin, A., Y. Garcia, Ph. Lanos, and F. Laubenheimer, Paleointensity geomagnetic field recovered on archaeomagnetic sites from France, Phys. Earth Planet. Inter., 120, 111–136, 2000.

  4. Coe, R. S., The determination of paleo-intensities of the Earth’s magnetic field with emphasis on mechanisms which could cause non-ideal behavior in Thelier’s method, J. Geomag. Geoelectr., 19, 157–179, 1967.

  5. Coe, R. S., C. S. Gromm, and E. A. Mankinen, Geomagnetic paleointen-sities from radiocarbon dated lava flows on Hawaii and the question of the Pacific non-dipole low, J. Geophys. Res., 83, 1740–1756, 1978.

  6. Etchevarne, C., A reciclagem da faiança em Salvador: contextos ar-queol’ogicos e tipos de utilização, Clio, 16, 2003.

  7. Etchevarne, C., Aspectos da cerâmica colonial do século XVII, em Salvador, Bahia, Clio, 20, 2006.

  8. Etchevarne, C., A faiança portuguesa do século XVII na Bahia. Patrimônio e Estudos, IPPAR, 10, 2007.

  9. Fox, J. M. W. and M. J. Aitken, Cooling-rate dependence of thermorema-nent magnetization, Nature, 283, 462–463, 1980.

  10. Gallet, Y., A. Genevey, and M. LeGoff, Three millennia of direction variation of the Earth’s magnetic field in Western Europe as revealed by archeological artefacts, Phys. Earth Planet. Inter., 131, 81–89, 2002.

  11. Gallet, Y., A. Genevey, and F. Fluteau, Does Earth’s magnetic field secular variation control centennial climate change?, Earth Planet. Sci. Lett., 236, 339–347, 2005.

  12. Genevey, A. and Y. Gallet, Intensity of the geomagnetic field in western Europe over the past 2000 years: New data from ancient French pottery, J. Geophys. Res., 107(B11), 2285, 2002.

  13. Genevey, A. S., Y. Gallet, and J. C. Margueron, Eight thousand years of geomagnetic field intensity variations in the eastern Mediterranean, J. Geophys. Res., 108(B5), 2228, 2003.

  14. G’omez-Paccard, M., A. Chauvin, Ph. Lanos, J. Thiriot, and P. Jiménez-Castillo, Archeomagnetic study of seven contemporaneous kilns from Murcia (Spain), Phys. Earth Planet. Inter., 157, 16–32, 2006.

  15. Gubbins, D., A. L. Jones, and C. C. Finlay, Fall in Earth’s Magnetic Field is Erratic, Science, 312, 900–902, 2006.

  16. Jackson, A., A. R. T. Jonkers, and M. Walker, Four centuries of geomagnetic secular variation from historical records, Phil. Trans. R. Soc. London A, 358, 957–990, 2000.

  17. Korte, M. and C. G. Constable, Continuous geomagnetic field for the past 7 millennia: 2.CALS7K, Geochem. Geophys. Geosyst., 6, 1, 2005.

  18. Korte, M., A. Genevey, C. G. Constable, U. Frank, and E. Schnepp, Continuous geomagnetic field models for the past 7 millennia: 1. A new global data compilation, Geochem. Geophys. Geosyst., 6, Q02H15, 2005.

  19. Kovacheva, M., Archeomagnetic database from Bulgaria: the last 8000 years, Phys. Earth Planet. Inter., 102, 145–151, 1997.

  20. Kovacheva, M., J. M. Parés, N. Jordanova, and V. Karloukovski, A new contribution to the archaeomagnetic study of a Roman pottery kiln from Calahorra (Spain), Geophys. J. Int., 123, 931–936, 1995.

  21. McIntosh, G., M. Kovacheva, G. Catanzariti, M. L. Osete, and L. Casas, Widespread occurrence of a novel high coercivity, thermally stable, low unblocking temperature magnetic phase in heated archeological material, Geophys. Res. Lett., 34, L21302, 2007.

  22. Morales, J., A. Goguitchaichvili, and J. Urrutia-Fucugauchi, A rock-magnetic and paleointensity study of some Mexican volcanic lava flows during the Latest Pleistocene to the Holocene, Earth Planets Space, 53, 893–902, 2001.

  23. Morales, J., L. M. Alva-Valdivia, A. Goguitchaichvili, and J. Urrutia-Fucugauchi, Cooling rate corrected paleointensities from the Xitle lava flow: Evaluation of within-site scatter for single spot-reading cooling units, Earth Planets Space, 58, 1341–1347, 2006.

  24. Néel, L., Some theoretical aspects of rock magnetism, Adv. Phys., 4, 191–243, 1955.

  25. Perrin, M. and E. Schnepp, IAGA paleointensity database: distribution and quality of the data set, Phys. Earth Planet. Inter., 147, 255–267, 2004.

  26. Soler-Arechalde, A. M., F. Sanchez, M. Rodriguez, C. Caballero-Miranda, A. Goguitchaichvili, J. Urrutia-Fucugauchi, L. Manzanilla, and D. H. Tarling, Archaeomagnetic investigation of oriented pre-Columbian lime-plasters from Teotihuacan, Mesoamerica, Earth Planets Space, 58, 1433–1439, 2006.

  27. Thellier, E. and O. Thellier, Sur l’intensité du champ magnetiqué terrestre dans le passé historique et géologique, Ann. Geophys., 15, 285–376, 1959.

  28. Valet, J.-P., Time Variations in Geomagnetic Intensity, Rev. Geophys., 41, 1, 2003.

  29. Yu, Y., D. J. Dunlop, L. Pavlish, and M. Cooper, Archeomagnetism of Ontario potsherds from the last 2000 years, J. Geophys. Res., 105(B8), 19419–19434, 2000.

Download references

Author information

Correspondence to Gelvam A. Hartmann.

Rights and permissions

Reprints and Permissions

About this article

Key words

  • Archeointensity
  • secular variation
  • cooling rate correction
  • Portuguese pottery